The biliary system delivers bile produced by the liver to the duodenum where the bile assists other gastric fluids in digesting food. The biliary system includes the liver, as well as a plurality of bodily channels and organs that are disposed between the liver and duodenum. When the liver produces bile, the bile enters biliary ducts that have relatively small cross-sectional areas, and that are dispersed throughout the liver. These biliary ducts carry the bile away from the liver and gradually merge with other biliary ducts. The last of the biliary ducts merge into the main biliary duct, from which the bile flows into the duodenum.
The biliary system also includes a gallbladder connected to one or more of the biliary ducts via the cystic duct. The gallbladder stores excess bile produced by the liver, and introduces the stored bile into the duodenum via the cystic duct and the biliary ducts when necessary.
Sometimes organic material (e.g., blood clots, tissue, and biological concretions such as urinary, biliary, and pancreatic stones) or inorganic material (e.g., components of a medical devices or other foreign matter) may obstruct or otherwise be present within the body's anatomical lumens, such as the biliary tree. For example, biological concretions can develop in certain parts of the body, such as kidneys, pancreas, and gallbladder. Minimally invasive medical procedures generally involve causing limited trauma to the tissues of the patient, and can be used to dispose of certain problematic biological concretions or similarly unwanted obstructions.
Lithotripsy and ureteroscopy, for example, may be used to treat biological concretions (e.g., kidney stones) in the body of patients. Lithotripsy is a medical procedure that uses energy in various forms, such as acoustic shock waves, pneumatic pulsation, electro-hydraulic shock waves, or laser beams, to pulverize biological concretions such as urinary calculi (e.g., kidney stones). The force of the energy, when applied either extracorporeally or intracorporeally, usually in focused and continuous or successive bursts, divides the concretion into smaller fragments that may be extracted from the body, or allowed to pass from the body, for example, through urination.
In certain instances, intracorporeal fragmentation of bodily concretions can become problematic if the stones or stone fragments, instead of progressing out of the patient's body, begin to migrate further into the body or towards an organ. In these circumstances, further medical intervention to prevent aggravation of the patient's condition may become necessary. Therefore, it may be desirable to be able to extract such fragments from the body using a single instrument, preventing the need for successive instrumentation which can cause greater trauma to the patient's tissue.
Accordingly, endoscopic procedures for treating abnormal pathologies within the alimentary canal system or biliary tree (including the biliary, hepatic, and pancreatic ducts) are increasing in number. Improvements in the quality of instrumentation have established endoscopy as a significant method of diagnosing and treating many pancreatic and biliary diseases. In general, for treatment of an abnormal pathology within a patient's body, an endoscope is first introduced into the body of the patient. The endoscope includes a proximal end and a distal end, and a lumen extending longitudinally therebetween. The endoscope may be guided through the patient's alimentary infrastructure until an opening at the distal end is proximate a desired location for gaining access to the area targeted for treatment. For example, treatment of the biliary tree may involve the distal end of the endoscope being positioned proximate the papilla of vater leading to the common bile duct and the pancreatic duct. At this point, the endoscope allows for components (e.g., catheters, stents, sphincterotomes, retrieval assemblies, and balloons) inserted through the lumen to access the targeted area and perform a desired operation.
Many stone extraction devices (e.g., stents, retrieval assemblies, and coiled medical extractions devices) can be used to entrap an object, such as a stone fragment, and drag it through an ampulla (i.e., a small dilatation in the patient's anatomical lumen) to remove it. However, occasionally an object may be too large to be extracted through an ampulla, or an obstacle is encountered upon forward movement of the stone fragment within the anatomical lumen. It may be necessary to provide further treatment, for example, lithotripsy or surgery.
Coiled medical extraction devices may also be used to prevent unwanted migration of stone fragments generated during a stone fragmentation procedure, and then safely and efficiently extract fragments from the patient's body. For example, during a lithotripsy procedure, a coiled medical extraction device can act as a backstop against any unwanted migration of stone fragments.